1. Field of the Invention
The present invention relates to a hydrophone assembly and a system and method for deploying the assembly, particularly in hydrophone arrays for underwater acoustic sensing of subsurface marine vehicles.
2. Description of the Related Art
Hydrophone arrays are used militarily to detect the presence of submarines and to provide information about their movements. Because modern submarines have the ability with cruise missiles to attack surface ships at great distances, the protection of surface shipping requires the ability to detect and track submerged submarines over vast areas of ocean. Hydrophone arrays have typically been used for this purpose.
Hydrophones are acoustic transducers that operate by detecting acoustic signals and converting them to electrical impulses that can then be transmitted by radio waves to a distant receiver. Typically, an array of hydrophones is loaded into a sonobuoy, which can then be dropped by airplane into the ocean. The array is then deployed while a float containing a transmitter remains at the surface of the water.
It is desirable to detect not only the presence and magnitude of acoustic signals, but also the direction of the signals. Various directional acoustic sensors are known. Such vector acoustic sensors often employ an accelerometer, which can add to the cost of such equipment. What is needed is a simple and less costly acoustic sensing system, which can also provide directional information about the received acoustic signals.